[src/jdolecek-ncq]: src/sys/dev/ic use free slot for drive reset, rather than...

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9a7d9e0e6dce
branches:  jdolecek-ncq
changeset: 822968:9a7d9e0e6dce
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Fri Jul 21 18:36:47 2017 +0000

description:
use free slot for drive reset, rather than always using slot zero; if we can't
get the slot, fallback to channel reset as usual

note this increases the odds of not being able to do the reset, when all slots
happen to be active

this is in same area as problem reported by PR kern/52372 but I
don't believe that this change actually make any change for it - during
probe/attach there shouldn't be any paralell request with drive reset

diffstat:

 sys/dev/ic/ahcisata_core.c |  33 ++++++++++++++++++++++-----------
 1 files changed, 22 insertions(+), 11 deletions(-)

diffs (98 lines):

diff -r 19f34186078d -r 9a7d9e0e6dce sys/dev/ic/ahcisata_core.c
--- a/sys/dev/ic/ahcisata_core.c        Fri Jul 21 18:12:37 2017 +0000
+++ b/sys/dev/ic/ahcisata_core.c        Fri Jul 21 18:36:47 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ahcisata_core.c,v 1.57.6.18 2017/07/19 20:21:42 jdolecek Exp $ */
+/*     $NetBSD: ahcisata_core.c,v 1.57.6.19 2017/07/21 18:36:47 jdolecek Exp $ */
 
 /*
  * Copyright (c) 2006 Manuel Bouyer.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ahcisata_core.c,v 1.57.6.18 2017/07/19 20:21:42 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ahcisata_core.c,v 1.57.6.19 2017/07/21 18:36:47 jdolecek Exp $");
 
 #include <sys/types.h>
 #include <sys/malloc.h>
@@ -650,7 +650,7 @@
 
 /* return error code from ata_bio */
 static int
-ahci_exec_fis(struct ata_channel *chp, int timeout, int flags)
+ahci_exec_fis(struct ata_channel *chp, int timeout, int flags, int slot)
 {
        struct ahci_channel *achp = (struct ahci_channel *)chp;
        struct ahci_softc *sc = (struct ahci_softc *)chp->ch_atac;
@@ -667,11 +667,13 @@
        else
                timeout = timeout / 10;
 
-       AHCI_CMDH_SYNC(sc, achp, 0, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+       AHCI_CMDH_SYNC(sc, achp, slot,
+           BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        /* start command */
-       AHCI_WRITE(sc, AHCI_P_CI(chp->ch_channel), 1 << 0);
+       AHCI_WRITE(sc, AHCI_P_CI(chp->ch_channel), 1 << slot);
        for (i = 0; i < timeout; i++) {
-               if ((AHCI_READ(sc, AHCI_P_CI(chp->ch_channel)) & 1 << 0) == 0)
+               if ((AHCI_READ(sc, AHCI_P_CI(chp->ch_channel)) & (1 << slot)) ==
+                   0)
                        return 0;
                is = AHCI_READ(sc, AHCI_P_IS(chp->ch_channel));
                if (is & (AHCI_P_IX_TFES | AHCI_P_IX_HBFS | AHCI_P_IX_HBDS |
@@ -708,6 +710,7 @@
        struct ahci_cmd_header *cmd_h;
        int i;
        uint32_t sig;
+       struct ata_xfer *xfer = NULL;
 
        KASSERT((AHCI_READ(sc, AHCI_P_CMD(chp->ch_channel)) & AHCI_P_CMD_CR) == 0);
 again:
@@ -732,9 +735,15 @@
                goto skip_reset;
 
        /* polled command, assume interrupts are disabled */
-       /* use slot 0 to send reset, the channel is idle */
-       cmd_h = &achp->ahcic_cmdh[0];
-       cmd_tbl = achp->ahcic_cmd_tbl[0];
+       /* use available slot to send reset, if none available fail */
+       xfer = ata_get_xfer_ext(chp, false, 0);
+       if (xfer == NULL) {
+               printf("%s: no xfer\n", __func__);
+               return 1;
+       }
+
+       cmd_h = &achp->ahcic_cmdh[xfer->c_slot];
+       cmd_tbl = achp->ahcic_cmd_tbl[xfer->c_slot];
        cmd_h->cmdh_flags = htole16(AHCI_CMDH_F_RST | AHCI_CMDH_F_CBSY |
            RHD_FISLEN / 4 | (drive << AHCI_CMDH_F_PMP_SHIFT));
        cmd_h->cmdh_prdbc = 0;
@@ -742,7 +751,7 @@
        cmd_tbl->cmdt_cfis[fis_type] = RHD_FISTYPE;
        cmd_tbl->cmdt_cfis[rhd_c] = drive;
        cmd_tbl->cmdt_cfis[rhd_control] = WDCTL_RST;
-       switch(ahci_exec_fis(chp, 100, flags)) {
+       switch(ahci_exec_fis(chp, 100, flags, xfer->c_slot)) {
        case ERR_DF:
        case TIMEOUT:
                aprint_error("%s channel %d: setting WDCTL_RST failed "
@@ -760,7 +769,7 @@
        cmd_tbl->cmdt_cfis[fis_type] = RHD_FISTYPE;
        cmd_tbl->cmdt_cfis[rhd_c] = drive;
        cmd_tbl->cmdt_cfis[rhd_control] = 0;
-       switch(ahci_exec_fis(chp, 310, flags)) {
+       switch(ahci_exec_fis(chp, 310, flags, xfer->c_slot)) {
        case ERR_DF:
        case TIMEOUT:
                if ((sc->sc_ahci_quirks & AHCI_QUIRK_BADPMPRESET) != 0 &&
@@ -811,6 +820,8 @@
            AHCINAME(sc), chp->ch_channel, sig,
            AHCI_READ(sc, AHCI_P_CMD(chp->ch_channel))), DEBUG_PROBE);
 end:
+       if (xfer != NULL)
+               ata_free_xfer(chp, xfer);
        ahci_channel_stop(sc, chp, flags);
        ata_delay(500, "ahcirst", flags);
        /* clear port interrupt register */